Digester top relief screen



Sept. 5, 1939. P. BOEHM DIGESTER TOP RELIEF SCREEN Filed Dec. 14, 1937 2Sheets-Sheet 1 gwum vbom alarm/um;

t. 5, 193 P. BOEHM DIGESTER TOP RELIEF SCREEN 2 Sheets-Sheet 2 FiledDec. 14, 1937 QYWMVMW 74 3060 227? GHQ mu Patented Sept. 5, 1939 UNITEDSTATES PATENT OFFICE DIGESTER TOP RELIEF SCREEN Paul Boehm, Rhinelander,Wis.

Application December 14, 1937, Serial No. 179,795

1 Claim.

This invention relates to a digester screen, the general object of theinvention being to provide a screen that can be readily removed forfilling of the digester and for cleaning purposes and one that has greatstrength so that it cannot collapse under digester pressure.

This invention also consists in certain other features of constructionand in the combination and arrangement of the several parts, to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claim.

In describing the invention in detail, reference will be had to theaccompanying drawings where- 25 in like characters denote like orcorresponding parts throughout the several views, and in which:

Fig. 1 is a top plan View of a digester with the cover removed and thescreen in place.

Fig. 2 is a view of the sleeve which is placed in 20 the neck of thedigester and carries the screen.

Fig. 3 is a sectional view on line 33 of Fig. l but with the cover inplace.

Fig. 4 is a top view of the sleeve with the screen removed.

25 In these drawings, the numeral I indicates the shell of the digesterand the numeral 2 the lining thereof. The sleeve is shown at 3 and isprovided with the ribs 4 which are embedded in the lining, as shown. Thesleeve is provided with a 30 flange 5 at its upper end which extendsover the top of the lining and rests on the top of the shell. The upperend of the sleeve has an annular seat 6 therein and the screen orstrainer 1 has its flat edge portion seated in this seat. The rest ofthe 35 strainer or screen is of concavo-convex shape and e'iftends intothe top of the sleeve so that the cover 8 can rest flat on the flange ofthe sleeve and over the screen or strainer without interference from thescreen.

As will be seen, the screen or strainer fits loosely in the sleeve sothat it can be removed to permit the digester to be filled and to enablethe screen to be cleaned. It can be removed without loosening any bolts,screws, nuts or the like. The cover 5 alone holds the screen in place.It has more reliefing capacity than any other top relief screen, used insulphite digesters, and it also has great strength and cannot collapseunder digester pressure. It is made of acid resisting material, such 10as bronze or stainless steel of various types.

It is thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction andin the combination and arrangement of the several parts, provided suchchanges fall within the scope of the appended claim.

Having thus described my invention what I claim and desire to protect byLetters Patent is:

In a digester for cellulous material, a neck having a top face forming aplane surfaced annulus, a sleeve fitted in said neck and having aperipheral flange having its under side forming a plane surface andresting on said top face, said sleeve having a rabbet extendingoutwardly from the inner surface of the sleeve at the top thereof,

a concave top relief strainer having a peripheral flange fitting in saidrabbet with the upper surface of the flange flush with the upper surfaceof the sleeve flange, said flush flanges forming an annular planesurface, and a cover plate resting on said flanges and having a planeunder surface whereby the cover plate has the combined functions ofclosing the device, of bearing downwardly on the sleeve flange in directcontact therewith and of holding the strainer in place.

PAUL BOEHM.

